Coating composition



Patented July s, 1941 2,248,961 COATING coiurosrrron Herbert c. Comstook, Mount Kisco, N. Y.

' No Drawing. Application June 21, 1938, Serial No. 214,938

3 Claims.

This invention relates to surface coatings and more particularly to the type which may be applied to a surface in liquid form by brushing,

spraying or dipping.

The invention further relates to a surface covering composition that may be applied to and bonded with practically any surface but is particularly well suited for application to metal surfaces as a rustproofing treatment. Not only does the invention comprehend a rustproofing material but the composition by simple application to surfaces, and particularly, metal surfaces, is admirably suited as a primer or surfacer for paint, varnish, lacquer, synthetic and other enamels and finishes.

For example, in the-automobile industry it has been common practice, in treating automobile body surfaces for the application of the top coats or finishing lacquers, to apply a number of aggregate coats, followed by a sanding or smoothing operation. According to the usual practice after the body surface has been cleaned, a rust inhibitor coat is applied which is baked or otherwise dried. Next is applied a primer coat which also requires baking. Then, from two to three coats of pigmented surfacer or filler (sometimes more, according to the price at which the car is to be sold) are applied, and these in turn are baked. This is followed by a sanding operation to smooth the surface preparatory to receiving the finishing coats.

It is one of the objects of this invention to eliminate a number of aforementioned operations in preparing metal surfaces, such as automobile bodies,?'for lacqueringor finishing coats while at the same, time producing a rustproofing treatment. l urthermore, not only is an effective rustprodfing treatment provided but the surface resulting from a single application of the composition comprehended by the invention is relatively {smooth and non-porous as compared to the surfaces produced by the: processes hereinabove 'mentioned. Consequently, according to the present invention very little sanding is required preparatory to application of the finishingcoats. Moreover, being less porous than pigmer ted fillers, the primer surfacer produced in accordance with the present invention requires a less number of finishing lacquer coats for'the desiredifinish, which can be brought more easily to a :higher briliiancy of luster and finish than couldbe produced over pigmented surfacers or undercoats. p, v

The invention, however, is not limited to automobile finishing but finds utility asa rustproofing treatment per se without additional coatings of lacquer or other finishes. According to the invention the composition also may serve as a vehicle for pigments to be used in place of or in conjunction with linseed oil or other common vehicles to improve the appearance, spreading and lasting qualities of the paints so compounded.

Stated generally, the invention consists in providing a composition by compounding a medium 011 varnish with a material which gives to the resulting composition a sustained flexibility, a material inert to oxidation to lend acid and alkali resistivity, a drying or oxidizable' oil and a quick evaporating material which serves to reduce the surface tension of the mixture when applied whereby. it will readily penetrate into pores,- cracks and crevices to give bonding qualities but which will quickly evaporate after the composition is applied to a surface to be coated.

The invention further consists in forming a product having the general characteristics, the new and useful applications, and the several features of utility hereinafter described and in the new and novel features of operation and the new determined amounts of beeswax, parailln wax, boiled linseed oil and mineral spirits. -When is hereinafter called properly compounded the composition thus formed may be variously modified depending upon the use to which it' is to be put. For convenience of description. the base material so formed "rustprooiing-primer-ve--v hicle.. It will be understood that the rustproofing-primer-vehicle may be used for certain purposes without further modification while other purposes may require additions or modifications to the rustproofing-primer-vehicle depending upon the use for which it is intended.

The following example is set forth as illustrative of one embodiment of the invention. A rustproofing-primer-vehicle may-be prepared by heating and stirring in a double jacketed boiler one and one-quarter gallons of medium oil varnish, three pounds of beeswax, and one-half pound of paraflin wax until all of these materials are thoroughly dissolved and intimately mixed. The temperature should be brought to approximately F. during this operation. After the foregoing are formed into a homoge- 'medium oil varnish" comprehends the varnish known generallyin-thetradebythatname. It is a varnish which comprises twentyto thirty gallonsofoilioeachlOOpoundsofgmnsor resins. I have found that a varnish containing 100 pounds of phenolic resins to twenty-four gallons-of China-wood oil produces very desirable results. The beeswax may be of a good commercial grade having a melting point of 140 to 150 F. The parailln should be of a good commercial grade having a melting point from 120 1". to 130 F. The mineral spirits which I have found to give best results has a distillation range of from 300-3-10 1'. (initial boiling point) to 890- 400 F. (end point). For purposes of safety the flash point should not be less than 100 1''.

The rustprooflng-primer-vehicle prepared in accordance with the foregoing. after cooling is then ready for use asa rustprooflng coating which may be applied directly to a clean metal surface and allowed to dry at atmospheric temperature or oven driedas desired. The coating thus applied constitutes an excellent rustprooflng treatment. It will be found to have penetrated the pores, cracks and crevices ofthe metal and has exceptional adhesive and bonding characteristics. It will remain in a sustained state of flexibility and will remain transparent.

. If desired, the rustprooflng-primer-vehicle may be prepared according to the following formula:

Per cent by weight Medium 011 varnish I 14.7 Beeswax 1.! Paraiiln wax .3 Boiled linseed oil 10.0 Mineral spirits-suflicient to make 100 I have found that the following method of compounding produces the desired results. To about half oi the medium oil varnish add the beeswax and paraflln and=heat to about 190 1". and stir until the waxes are thoroughly dissolved. then add the linseed oil with constant stirri until the mixture is homogeneous. Then add about a tenth of the mineral spirits and the remainder of the medium oil varnish. Heat this mixture to about 170 F. and add the remainder of the mineral spirits. Stir the mixture thoroughly for about ten minutes, reheat to about 198 F. and allow to stand for about 40 minutes at that temperature. v This mixture is then cooled.

To make a one coat transparent, non-pigment rustprooilng primer and surfacer, that is, as a base coat for applying lacquer or other finishes, mix two parts of the rustprooflng-primer-vehicle with one part of medium oil varnish. A composipigmentpr'imerandsurfaeer". mammals percentage by weight basiswill be as follows:

While the preferred formula for the non-pi mentprimerandsurfacerhasbeensetforththe invention is not intended necessarily to be limited to the precise percenteses as it has been found that the amount of beeswax may vary from about 1% to about 8% with desirable results and the paraffin wax may vary from about 0.1% to about 1.0% with percentages of the other ingredients remaining approximately the same.

The use of the non-pigment primer and surm facerwillbedescribuiinconnectionwithflnishing an automobile body although it will be apparent as the description proceeds that other metal surfaces may be similarly treated.

After the surface of the body has been cleaned 2 in the usual manner one coat of the non-pigment primer and surfacer is sprayed on the body. The body is then oven dried for approximately one hour at about 200 1". Or, if desired, this oven drying may be accelerated by increasing the temperature. If the drying temperature is increased to 800 F. the requisite drying will require only about nfteen minutes.

After drying, the non-pigment primer and surfacer will require very little, if any. sanding as it will be found that the surface drys smooth and a non-porous coating is tenaciously bonded to the metal by reason of its having penetrated into pores and crevices. The body is then ready for application of lacquer ilnisha in the usual way and it has been found that three sprayed costs of the latter will be sufllcient whereas in processes now commonly used over porous or pigmented undercoats, more coats of lacquer are generally quired.

Consequently. the invention effects economies,

- in floor space, ovens, number of operations, and time schedules in addition to savings in materials while at the same time affording an eifective 'rustprooflng treatment by a protective coating which will have excellent adhesive and flexibility characteristics.

In addition to the foregoing mentioned uses the rustproofing primer vehicle composition comprehended by the invention may serve as a vehicle for white lead; red lead and other paint pigments. For example, red lead mixed with the rustprooflng-primer as the vehicle when used as a prime or base coat (outdoors, as on structural steel bridges) will dry over night free from tack,

00 and cover more than twice the surface area, than an equal quantity of the same red lead mixed with a like amount of linseed oil used as the vehicle. The vehicle will penetrate the crevices and pores in the steel and the paint so made provides 05 a most effective rust repellant base.

The term rustprooiing" as herein used is intended as a word of description and to have its usual connotation as generally understood in the trade since by its nature it is a relative term.

7 Herein, it is intended to connote that characteristic of inhibiting oxidation for abnormally extended periods of time as it is generally known that all oxidizable metals, if exposed to oxidants indefinitely. will finally become oxidized to a tion so made is herein referred to as a nongreaterorlessdegree.

Likewise, other terms and expressions which 1 scription, and there is no intention, in the use ofsuch terms and expressions, of excluding equivalents of the features described, but it is reco nized that various modifications are possible within the scope of the claims hereto appended.

What is claimed is:

1. A liquid vehicle for paint pigments comprising a mixture of ingredients in approximate proportions as follows: three and one-half gallons of medium oil varnish containing not more than eleven and six-tenths pounds of gums and resins, three pounds of beeswax having a melting point of 140 to 150 F., one-half pound of paraffin wax having a melting point from 120 to 130 F., two and one-quarter gallons of boiled linseed oil and nineteen and one-half gallons of mineral spirits having an initial boiling point of 300-310 F. and an end point of 390-400 F.

2. A composition consisting of medium 011 varnish approximately 14.7% by weight, beeswax having a melting point 140-150 F. approximately 1.7% by weight, paraflin wax approximately 0.3%, boiled linseed oil approximately 10%, balance mineral spirits having an initial boiling point and an end point of about 300 F. and 400 F. respectively to make 100% by weight, said composition being in the form of a homogeneous liquid and being characterized by drying rapidly when applied to clean metal surfaces leaving a transparent, permanently flexible coating tenaciously bonded thereto.

3. A composition comprising medium oil varnish approximately 17.6% by weight, beeswax having a melting point 140-150 C. approximately 1.6% by weight, paraffin wax having a melting point 120-130 F. approximately 0.3% by weight, boiled linseed oil approximately 9.6% by weight, balance mineral spirits having an initial boiling point 300-310 F. and an end point 390-400 F. to make 100% by weight, said composition being characterized by its property of drying rapidly when applied to a clean metal surface leaving a single transparent flexible primer and surfacer coating tenaciously bonded to said metal surfaces.

HERBERT C. COMSTOCK. 

